package spec.lijunyao.unit4.outclazz;
/*
* 内置类的测试
* */
public class Test11 {
    public static void main(String[] args) {
        //Math 类测试
        double d=Math.sin(Math.PI/5);
        System.out.println(d);
        System.out.println(Math.sqrt(1000));


        //StringBuffer类测试
        StringBuffer sb =new StringBuffer("abcdefgHIJKL");
        System.out.println(sb.length());
        System.out.println(sb);
        sb.insert(1,"M");
    }
}
